Rathke cleft cyst presenting as unilateral progressive oculomotor nerve palsy

A rare case of isolated ACTH deficiency associated with a Rathke's Cleft Cyst and a review of the literature

A 78-year-old man was referred to clinic due to a 5-year history of weight loss, lethargy, and pathology showing hyponatremia. In the year prior, he had a hospital admission for symptomatic hyponatremia. MRI brain during that admission showed a 1-2 mm pituitary lesion of unknown significance. Testing during this presentation revealed hypocortisolism with ACTH deficiency. Progress MRI brain revealed the presence of a Rathke's Cleft Cyst (RC). Medical management with glucocorticoids resulted in symptomatic and biochemical parameter improvement. To our knowledge this is the first reported case of isolated ACTH deficiency in the setting of a RC.

Rathke Cleft Cyst with Occulomotor Palsy: An Unusual Presentation

Rathke cleft cysts arise from remnants of Rathke's pouch. Often identified as incidental autopsy findings, these cysts can occasionally become large enough to cause headache, vision impairment, hypothalamic pituitary dysfunction and rarely, cranial neuropathy. MRI is the imaging modality of choice with surgical drainage recommended in symptomatic cases.

Intermittent oculomotor nerve paresis and hollow appearance on MRI manifested by pituitary adenoma

A 71-year-old man had sustained intermittent ptosis and double vision for 2 weeks. Neurological examination found unilateral oculomotor nerve (CN III) paresis manifesting as limitations of gaze, ptosis, and mydriasis. Neither headache nor any other cranial neuropathy was noted. Cerebral magnetic resonance imaging revealed a well-circumscribed mass in the pituitary fossa extending laterally into the left cavernous sinus. The segment of the left CN III lying in the oculomotor cistern was considerably compressed by the tumor. The cisternal segments of the left CN III showed an undescribed, “hollow” appearance. The left orbit and brainstem were intact. The patient underwent tumor resection via an endoscopic transsphenoidal approach. The tumor tissue was soft in consistency, involving xanthochromic fluid. The pathological diagnosis was pituitary adenoma accompanied with considerable hemorrhagic changes. The patent's ptosis and limitations of gaze showed remarkable improvements on postoperative day 1, with resolution of the hollow appearance of the affected CN III that was confirmed on day 3. We assumed that the intralesional bleeds and lateral tumor extension into the oculomotor cistern were associated with the intermittent paresis of the CN III as the sole presentation. A hollow appearance identified in the CN III might indicate a reversible dysfunction of the nerve that can anticipate an improvement by prompt surgical intervention.